Field of the Invention
The invention concerns a weighing method; an arrangement for implementation of a weighing method, and a corresponding computer-readable storage medium in the field of dynamic weighing in mail processing. A particular field of use is the determination of weights of mail pieces with the use of a dynamic scale.
Description of the Prior Art
Various solutions are known in the field of dynamic weighing in mail processing. In particular, horizontal systems or vertical systems (108°) are used.
Customer requirements are set in particular for the throughput of these systems. The throughput D of a franking machine is determined as the number of letters per time unit. With a given transport velocity v and a letter interval x (edge-to-edge, thus leading edge of a letter to leading edge of a letter), D=v/x results. This means that, in order to increase the throughput, the transport velocity of the letters must thus be increased and/or the interval between the letters must be reduced.
One criterion for the throughput is the weighing speed. For example, an algorithm to determine the weighing result is described in the Patent Document EP 1 014 052 B8. Other solution approaches to increase throughput by shortening the interval between the letters are known from the publication US 2009/0008859 A1. There, a system is described in which at least two shorter weighbars are operated in series. Short letters may be weighed with a short interval by means of one weighbar; given long letters, the weighing result is a superposition of the weighing results of both weighbars.
An additional solution is the parallel arrangement of two weighbars (described in the publication US 2009/0139777 A1) so that the throughput can be increased via parallelization of the weighing process. However, additional devices are necessary for this to divide and merge the letter stream before and after the scale, which drives up the space requirement.
Furthermore, under DE 10 2010 009 431 A1 a solution was disclosed that describes a shortened scale with a draw-off device.
A scale with cascaded weighing cells is known from the publication DE 10 2011 100 176 A1.
In tests, it has been shown that the algorithm described in EP 1 014 052 B8 is not sufficiently robust for a scale with cascaded weighing cells.